am e5879c36: Byte swap to support BGRA in recovery mode

static gr_surface fbdev_flip(minui_backend* backend __unused) {

    if (double_buffered) {

#if defined(RECOVERY_BGRA)

        // In case of BGRA, do some byte swapping

        unsigned int idx;

        unsigned char tmp;

        unsigned char* ucfb_vaddr = (unsigned char*)gr_draw->data;

        for (idx = 0 ; idx < (gr_draw->height * gr_draw->row_bytes);

                idx += 4) {

            tmp = ucfb_vaddr[idx];

            ucfb_vaddr[idx    ] = ucfb_vaddr[idx + 2];

            ucfb_vaddr[idx + 2] = tmp;

        }

#endif

        // Change gr_draw to point to the buffer currently displayed,

        // then flip the driver so we're displaying the other buffer

        // instead.